[dpdk-users] Cross compile for ARM64 fails due to librte_vhost and pmdinfogen issues

[Michael Wildt]

Hi Thomas,

Appreciate the assistance. Please see inline.


On Tue, Sep 13, 2016 at 5:03 AM, Thomas Monjalon <thomas.monjalon at 6wind.com>
wrote:

> Hi,
>
> 2016-09-12 22:20, Michael Wildt:
> > I'm attempting to cross compile DPDK on an x86 for an ARM64 target. This
> > fails in the following areas, using latest dpdk as of 9/12. When
> compiling
> > natively there are no issues.
>
> Your analysis below seems good.
> Interestingly, I do not see such error (don't know why).
> Please could you share the commands you are using?
>

Sure can.

make config T=arm64-armv8a-linuxapp-gcc CROSS=/projects/ccxsw/
toolchains/gcc-linaro-aarch64-linux-gnu-4.9-2014.09_linux/bin/aarch64-linux-gnu-
ARCH=arm64

make T=arm64-armv8a-linuxapp-gcc CROSS=/projects/ccxsw/
toolchains/gcc-linaro-aarch64-linux-gnu-4.9-2014.09_linux/bin/aarch64-linux-gnu-
ARCH=arm64 RTE_KERNELDIR=/projects/kernel

Thanks,
Michael



> > - librte_vhost, fails with:
> >
> > /projects/dpdk_latest/lib/librte_vhost/vhost_user/virtio-
> net-user.c:250:23:
> > error: array subscript is above array bounds [-Werror=array-bounds]
> >    rvq = dev->virtqueue[i * VIRTIO_QNUM + VIRTIO_RXQ];
> [...]
> > - buildtools/pmdinfogen, fails with:
> >
> > == Build buildtools/pmdinfogen
> >   HOSTCC pmdinfogen.o
> > /projects/dpdk_test_wget/dpdk-16.07/build/include/rte_byteorder.h:
> > Assembler messages:
> > /projects/dpdk_test_wget/dpdk-16.07/build/include/rte_byteorder.h:53:
> > Error: no such instruction: `rev16 %bx,%bx'
> [...]
> >   - The issue is due to the rte_byteorder.h file which gets symlink'ed
> with
> > the ARM version at the beginning of the build. The pmdinfogen is always
> > compiled for x86 thus the asm is failing. I see two ways to address this.
> >
> > - Have pmdinfogen always pickup the local OS rte_byteorder.h file, not
> the
> > ARCH symlinked one.
>
> Yes we should not use DPDK headers in pmdinfogen or have a host-include/.
>
> > - Fix pmdinfogen such that it gets cross compiled correctly as the rest
> of
> > the code. Did a quick attempt by setting the HOST_OS to 0, , but then it
> > fails at the HOST_LD.
>
> No it must be native because it is part of the build system.
>